Dispenser and method of dispensing and controlling with a flow meter

Abstract

A non-contact jetting dispenser, viscous fluid dispensing system and method. The system includes a viscous fluid dispenser for dispensing the viscous fluid. The system further includes a viscous fluid supply container adapted to hold the viscous fluid. A flow path is provided for the viscous fluid between the viscous fluid supply container and an outlet of the viscous fluid dispenser. An electronic flow meter device is used to produce electrical output signals proportional to the flow rate of the fluid flowing through the flow path. A control is operatively coupled to the electronic flow meter for continuously receiving and processing the electrical output signals and performing a responsive control function in a closed loop manner.

What is claimed is: 
     
       1. A viscous fluid dispensing system for accurately dispensing viscous fluid and controlling a dispensing operation, the system comprising:
 a viscous fluid dispenser including an inlet and an outlet, the dispenser being operable to start and stop the flow of the viscous fluid from the outlet onto a substrate; 
 a viscous fluid supply container adapted to hold the viscous fluid, and having an outlet coupled in fluid communication with the inlet of the viscous fluid dispenser to establish a flow path for the viscous fluid between the viscous fluid supply container and the outlet of the viscous fluid dispenser, the viscous fluid supply container further including an pneumatic input adapted to receive pressurized air for forcing the viscous fluid from the outlet of the container; 
 an electronic flow meter device operatively coupled in the pneumatic input of the container to produce electrical output signals proportional to the flow rate of the pressurized air received through the pneumatic input when the fluid is being dispensed from the outlet; and 
 a control operatively coupled to the electronic flow meter for continuously receiving and processing the electrical output signals and performing a responsive control function in a closed loop manner. 
 
     
     
       2. The viscous fluid dispensing system of  claim 1 , wherein the electrical output signals are in the form of an output data set, a reference data set is stored in the control, and the processing includes comparing the output data set to the reference data set. 
     
     
       3. The viscous fluid dispensing system of  claim 1 , wherein processing the electrical output signals further comprises detecting a discrepancy in the flow rate of the viscous fluid flowing through and being dispensed from the outlet of the dispenser, and the responsive control function further comprises making an adjustment to change the flow rate of the viscous fluid flowing through and being dispensed from the outlet of the dispenser. 
     
     
       4. The viscous fluid dispensing system of  claim 1 , wherein processing the electrical output signals further comprises detecting an air bubble in the viscous fluid flowing through the dispenser. 
     
     
       5. The viscous fluid dispensing system of  claim 4 , wherein performing a response control function further comprises providing an indication to an operator that an air bubble has been detected. 
     
     
       6. The viscous fluid dispensing system of  claim 1 , wherein processing the electrical output signals further comprises detecting a clogged or semi-clogged condition of the dispenser. 
     
     
       7. The viscous fluid dispensing system of  claim 6 , wherein performing a responsive control function further comprises providing an indication to an operator that the clogged or semi-clogged condition has been detected. 
     
     
       8. The viscous fluid dispensing system of  claim 1 , wherein the control operates to process the electrical output signals and perform the responsive control function while the viscous fluid dispenser is dispensing the viscous fluid onto the substrate. 
     
     
       9. The viscous fluid dispensing system of  claim 1 , wherein the control operates to process the electrical output signals and perform the responsive control function while the viscous fluid dispenser is located away from the substrate and at a calibration station. 
     
     
       10. A method of controlling a viscous fluid dispensing system to accurately dispensing viscous fluid, comprising:
 directing a viscous fluid from a viscous fluid supply container into a dispenser using pressurized air flowing through a pneumatic input of the viscous fluid supply container; 
 discharging the viscous fluid from an outlet of the dispenser; 
 using an electronic flow meter device operatively coupled to the pneumatic input of the viscous fluid supply container to produce electrical output signals proportional to the flow rate of the pressurized air flowing through the pneumatic input; and 
 processing the electrical output signals and performing a responsive control function in a closed loop manner. 
 
     
     
       11. The method of  claim 10 , wherein the electrical output signals are in the form of an output data set, a reference data set is stored in the control, and the processing includes comparing the output data set to the reference data set. 
     
     
       12. The method of  claim 10 , wherein processing the electrical output signals further comprises detecting an discrepancy in the flow rate of the viscous fluid flowing through and being dispensed from the outlet of the dispenser, and the responsive control function further comprises making an adjustment to change the flow rate of the viscous fluid flowing through and being dispensed from the outlet of the dispenser. 
     
     
       13. The method of  claim 10 , wherein processing the electrical output signals further comprises detecting an air bubble in the viscous fluid flowing through the dispenser. 
     
     
       14. The method of  claim 13 , wherein performing a response control function further comprises providing an indication to an operator that an air bubble has been detected. 
     
     
       15. The method of  claim 10 , wherein processing the electrical output signals further comprises detecting a clogged or semi-clogged condition of the dispenser. 
     
     
       16. The method of  claim 15 , wherein performing a responsive control function further comprises providing an indication to an operator that the clogged or semi-clogged condition has been detected. 
     
     
       17. The method of  claim 10 , wherein processing the electrical output signals and performing the responsive control function occur while the viscous fluid dispenser is dispensing the viscous fluid onto a substrate. 
     
     
       18. The method of  claim 10 , wherein processing the electrical output signals and performing the responsive control function occur while the viscous fluid dispenser is located away from a substrate and at a calibration station.